What are some common heuristics that might be innate?
Perhaps Occam's razor counts. 

Occam's razor is the meta-heuristic that "the simplest explanation is the most likely to be correct". I consider it a meta-heuristic because itself doesn't provide explanations, only means of comparing them among another. It is a heuristic because like all heuristics, it can lead to false conclusions, but is usually right.